With legislative leaders still working on the finer points of a plan to send money to public schools, their efforts risked being derailed amid ongoing rancor between Gov. Bruce Rauner and Mayor Rahm Emanuel as well as pressure from unions.

On Sunday, Republican leaders tried to downplay the strife as they headed into the latest round of closed-door negotiations at the Capitol, saying dissatisfaction on both sides was a sign of compromise. A vote on the proposal could come as early as Monday in the House.

"There's a lot of issues in here that are tough," said House Republican Leader Jim Durkin of Western Springs. "But at the end of the day, every school, every family and every child is going to benefit from this."

The tentative agreement is the result of talks between the four Democratic and Republican legislative leaders in the wake of Rauner's veto of a plan to overhaul how taxpayer dollars are distributed to school districts across the state. Without a new funding formula in place the state cannot cut checks, and schools already have missed two payments.

Democrats took umbrage with a provision that would provide $75 million in tax credits for those who donate scholarship money to private schools, which teachers unions have railed against as a way to take funds away from public education. The Republican governor argued the deal would still set aside too much money for troubled Chicago Public Schools, even after his office issued a statement Thursday saying he looked forward to "when the legislation is passed."

The leaders recently held several closed-door meetings in search of a compromise after...

The four Democratic and Republican legislative leaders said Thursday that they have reached a tentative agreement with Gov. Bruce Rauner on a plan to fund schools, though the sides warn a deal is not yet final.

The leaders recently held several closed-door meetings in search of a compromise after...

(Monique Garcia, Hal Dardick and Juan Perez Jr.)

A day later, during a visit to southern Illinois, Rauner had all but reverted to campaign mode. He lashed out at his chief political nemesis, Democratic House Speaker Michael Madigan, and played regional politics by repeating his longstanding contention that the measure helped CPS at the expense of others.

"It's not fair, but it's going to end up being a compromise," Rauner said. "It's not where we would like it to be. And what I'll try to do is fix the problems with it in subsequent legislation."

What happened in a day to change Rauner's tone?

Even before the accord was announced, Emanuel poked Rauner over his decision to shed his new press staff just weeks after bringing them on amid a massive staff shakeup in the governor's office.

"I kind of think some guy that's talked about running on a 'turnaround agenda,' it's becoming quite apparent that it's a 'turnover agenda,'" Emanuel said, mocking the tagline Rauner had given to his pro-business wish list.

Later, during a news conference on the school funding announcement, Emanuel boasted it would give CPS everything it had wanted "and more" than the plan Rauner rewrote to try to reduce state aid to the district.

If Rauner considers the issue unfinished, some Republican lawmakers could vote against it. Already, some Republicans have complained that the near-deal basically leaves Chicago unscathed from an original plan that they and Rauner for weeks have decried.

"(Rauner) has railed about the 'Chicago bailout' for a long time. I want to make sure Chicago school kids are well-educated and taken care of," McSweeney said. "But the governor spent months railing against this thing. Mayor Emanuel shows up on Thursday night with a big smile on his face."

To gain GOP support, the bill includes a new $75 million private-school tuition tax credit. That would allow a state income tax deduction of 75 cents on the dollar for donations made to a scholarship plan that would help pay for tuition for students to attend private schools.

Many House Democrats, particularly those heavily backed by the Chicago Teachers Union, expressed anger over that aspect when briefed on it Friday morning. They contend the proposal would not only take money from state government but also lead to fewer students attending public schools, reducing the amount of state aid they receive.

"I'm caught between a rock and a hard place, and I think a lot of my colleagues feel the same," Rep. Theresa Mah, D-Chicago, a co-sponsor of the original legislation vetoed by Rauner, said on WGN 720-AM.

If the combination of factors holds off enough votes, plans for a Monday roll call on the proposed agreement could collapse — and that could play into Democratic hands.

Tuesday marks the deadline for the House to consider an override of Rauner's rewrite of the original Democratic-passed measure. The Senate already has overridden Rauner, and if lawmakers are convinced that it may be the last chance to keep schools open throughout the school year, it could put pressure on reluctant Republicans to support the override.

Such a scenario would mark another significant defeat for the reelection-seeking governor after the Democratic-led General Assembly, with the help of some Republicans, disregarded Rauner vetoes and enacted a state budget and tax package that effectively ended a two-years-long impasse.

The leaders are scheduled to meet again Monday morning to "try to finish working through the small details," ahead of a potential vote, said Madigan spokesman Steve Brown.